Molly Picklum will be looking to bed down a place in the top-five World Surf League Finals when competition gets under way in the Championship Tour's penultimate round in Brazil.
With one event remaining after Rio, at Fiji's Cloudbreak, surfers are scrambling to make the top five who will surf in a one-day winner-takes-all contest at California's Lower Trestles in September.
There are three Australians currently inside the cut-off, with Picklum ranked fourth in the women's competition.
Current world No.2 Jack Robinson is the top Australian man while Ethan Ewing sits in fourth spot.
Two-time world champion Tyler Wright, currently ninth, faces a near-impossible battle to make the top five after withdrawing from the Rio Pro with a foot injury.
The competition window for the Brazil event at Praia de Itauna opens on Sunday (AEST) with favourable conditions forecast.
Caitlin Simmers will defend her 2023 title and look to extend her lead at the top of the rankings, with a strong result also guaranteeing her spot in the WSL Finals.
The 18-year-old sits just 440 points clear of fellow American and reigning world champion Caroline Marks.
Hawaii's John John Florence has a healthy lead in the men's rankings and has already clinched his spot in the title decider.
Florence has won twice in Brazil - in 2012 and 2016 - with both events surfed at Barra da Tijuca in Rio de Janeiro before it was relocated to Saquarema.
"My first win ever here was at the Rio Pro, I was really excited about that," Florence said.
"I remember there was a year when Filipe (Toledo) won and that was the biggest crowd I've ever seen for a surf contest.
"I'd never seen anything like that, it was pretty crazy. The support behind surfing here is crazy, it really is amazing."
Last year, Picklum made the Rio Open quarter-finals, Robinson bowed out early and Ewing lost the final to home-town hero Toledo.
Picklum will surf in the women's opening heat against French world No.5 Johanne Defay and 10th-ranked American Sawyer Lindblad.
Ewing has also drawn an opening heat, lining up against Sydneysider Connor O'Leary, who now surfs for Japan, and American Cole Houshmand, with both well down the rankings.
Robinson's first battle is with compatriot Ryan Callinan, ranked 15, and local hope Samuel Pupo, who is world No.23.
